With the rising energy cost, energy conservation and effective distribution of energy consumption have taken on increasing importance.
Utility companies have introduced and deployed numerous technologies to help manage electricity demand during peak hours, although most of this effort thus far has been directed at utility's commercial customers through technologies such as AutoDR (Automated Demand Response). See, e.g., Allen Chen, “Automated Demand Response—How the internet helps the electricity grid in California”, Mar. 5, 2008, http://drrc.lbl.gov/pubs/sci-lbnl-3-5-08-adr.pdf. AutoDR allows the utility company to automatically demand its AutoDR customers' electrical appliances to automatically lower their energy consumption during peak energy use periods to prevent brown outs or black outs.
Most consumers have no knowledge on the energy consumption levels of various household appliances and electrical devices which consume electricity and generally rely on common sense to conserve electricity use. With the advent of home automation technologies both in the wireless and power-line based areas, an increasing number of devices and technologies are being offered to the consumers to perform smart energy management in a consumer household. Such technologies include, for example, Insteon™, Z-Wave®, ZigBee®, Echelon®, and the like.
Insteon™ technology from SmartLabs, Inc., is one of the most popular home automation technologies on the market. Insteon™ technologies implement a dual-mesh network, which essentially means that the Insteon™ technologies support two means of communication to back each other up: radio frequency signals and the home's existing electrical wiring. All Insteon™ devices are peers, meaning that any Insteon™ device can transmit, receive, or repeat messages from other peers without a master controller or elaborate routing software. The frequency that the Insteon™ RF devices send transmissions is 904 MHz, and the raw sustained Insteon™ bitrate stands at 2,880 bps for both standard and extended messages.
The Z-Wave® protocol is an interoperable wireless communication protocol that is also implemented in home automation necessities. Because a Z-wave® network is not peer-to-peer, it is substantially more arduous to synchronize all the additional Z-wave® devices to other Z-wave® enabled devices than Insteon™ devices. Also, the Z-Wave® protocol is entirely reliant on radio signals thus causing its designers gave it a significant number of complex features to augment its reliability. The frequency at which a Z-Wave® network transfers messages is 908.42 MHz in the United States, while it stands at 868.42 MHz in Europe. A Z-Wave® network routes messages through its network using the Source Routing Algorithm (SRA) which requires message initiator to know the network topology so it can compute the best route to send the message. Low-end Z-Wave® devices incapable of routing messages are called slaves. A Z-Wave® network relies on a central control unit called a Static Update Controller (SUC) to manage message routing within a Z-Wave® network. The Z-Wave® protocol is backed by Zensys A/S, now a division of Sigma Designs, Inc. Zensys A/S supplies Z-Wave® chips; Zensys A/S is also the assignee of U.S. Pat. No. 6,879,806, entitled “System and method for building routing tables and for routing signals in home automation.”
ZigBee® technology is a cost-effective, power-efficient, wireless technology that is frequently used as an alternative to both Bluetooth® technology and Wi-Fi® technology. Like all the technologies listed above, ZigBee® technology establishes a mesh network between nodes. ZigBee® technology relies on IEEE 802.15.4 radios, which transmits at a frequency of 2.4 GHz and 915 MHz in the United States while it transmits at a frequency of 2.4 GHz and 868 MHz in Europe. ZigBee® technology establishes an application/framework and network/security layers on top of existing IEEE 802.15.4 standards. The data rate of ZigBee® networks varies depending on the frequency at which the IEEE 802.15.4 transmits. The network layer of ZigBee® software supports star, mesh, and cluster tree (hybrid of star and mesh) network topologies. ZigBee® technology is defined by two kinds of devices: FFDs (full function devices), and RFDs (reduced function devices). Typically line powered, FFDs can communicate with all other FFDs and RFDs, act as network and link coordinators, discover other FFDs and RFDs, and can perform all of the RFD's functions. RFDs can be installed only in a star network because they can communicate with only the FFD network communicator. To support device interoperability, ZigBee® devices support a number of “profiles” and there are currently a number of private profiles supported by private manufacturers and public profiles supported by the ZigBee Alliance®.
Echelon LONWORKS® is a networking platform that is generally used to network devices over fiber optics, power lines, twisted pair, coax, infrared, and radio, with the majority of installations using dedicated twisted pair wiring. Deployed mainly in building and factory automation and commercial control, Echelon LONWORKS® is a sophisticated routed network that uses loop-free (learning) routers and repeaters to send transmissions reliably. Intended as a BACnet (Building Automation Control network) replacement, the LONWORKS® uses a protocol called LONTALK®, standardized with ANSI/CEA 709.1 and IEEE 1473-L. LONWORKS® is a routed network that uses learning routers and repeaters to deliver messages consistently and reliably. For manufacturers implementing the LONWORKS® networking platform and its LONTALK® protocol, Echelon® technology embeds the protocol stack and processing power into a Neuron® semiconductor to simplify the productization process. The LONTALK® protocol design follows the International Standards Organization's Reference Model for Open Systems Interconnection (ISO OSI), which prescribes the structure for open communications protocols. LONWORKS® is unique in that it is the only control protocol that implements all seven layers of this model. The LONTALK® protocol defines a hierarchical form of addressing using domain, subnet, and node addresses. This form of addressing can be used to address the entire domain, an individual subnet, or an individual node. Interoperability among different LONWORKS® devices from different manufacturers is achieved through the use of Standard Network Variables Types or SNVTs and the binding of SNVTs.
There are numerous home automation and energy management products in the market today based on the above mentioned technologies: Insteon™, Z-Wave®, ZigBee®, and Echelon LONWORKS®. However, all of these products operate strictly within the realm of the technology they are based on, and tend to operate independently and passively follow the protocol dictated by the technology to perform a fixed function. These products typically lack an application layer which operates above the underlying technology platform to deliver a specific result through collaboration of a collection of related products.
Various solutions for electrical load shedding control arrangement exist. In published U.S. Patent Application No. 2005/143856, Gardner teaches a system and method that accepts commands from the utility companies to control household appliances such as an air conditioner to reduce electricity consumption for settable periods of time during peak demand period (to prevent occurrences like brownouts). In U.S. Pat. No. 6,891,478, Gardner teaches a system that distributes power to various electronic appliances. However, Gardner's solution relies solely on the power lines to distribute the power, and the devices directly transfer the power from one device to another. Gardner's solution is directed toward households with a generator, as opposed to power from a plant. In addition, Gardner's solution features a centralized control unit wherein the intelligence of the system resides. In U.S. Pat. No. 5,675,503, Moe teaches a system that uses historical performance data of an electrical appliance, such as an air conditioner, to determine how to best cycle the appliance to meet the load shedding demands requested from a local utility company while maintaining indoor temperature within an acceptable range.
However, all the solutions described above deal with a centralized power monitoring and control system with power management intelligence centralized at a central server/controller located either at the utility company or at a central power generating source. The solutions described above provide energy management and load shedding control based on commands issued and/or programmed from a centralized server/controller device. These prior solutions rely on an expensive centralized server in order to operate, and have slow performance due to the need to always check with a centralized server in order to perform its functions and lack of extensibility as new devices may be difficult to be added to the network without reprogramming the centralized server. None of these solutions provide for individual electricity consuming devices to negotiate among themselves to achieve a desired energy consumption level in a household or a commercial building.
Accordingly, a need exists for an improved solution for home automation management. A further need exists for such a solution that allows household or commercial appliances to dynamically negotiate to achieve desired energy savings results.